Throttle handle for fluid-pressure tools



Feb. 8, 1927.

E.' W. STEVENS 'EHROTTLE HANDLE FOR FLUID PRESSURE TOOLS Filed April 20-, 1925 izvvzwron row/1R0 WSTEI/ENS" rica;

EDWARD w. s'rEvENs, oEnE'rR'orr, MICHIGAN, ASSIGNOR T0 CHICAGO PNEUMATIC TOOL compan or NEW YORK, N. Y., A CORPORATION OF NEW JERsEY.

THROTTLE HANDLE FOR FLUID-PBESSURETOOLS.

Application filed April 20, 1925. Serial no. 24,410.

' other small pneumatic tools. Still more specifically it relates to devices of this kind commonly known as lift trigger handles.

One object of the invention is to provide a lift trigger handle which is lighter and more compact than those heretofore used and which will facilitate the carrying of the tool without danger of-the accidental opening of the'throttle. Another object'is to provide an improved arrangement of levers for operating the throttle valve but which will permit free movement of the triggerto a limited extent. parent from the detailed description which follows.

In order to illustrate the invention and the manner of its use one concrete embodiment thereof is shown in the accompanying drawings, in which: a i Fig. 1 shows a fragmentary view of a pneumatic hammer provided with a handle according to the present invention shown in vertlcal section;

Fig. 2 is a view similar to Fig. 1 showing the control means for the throttle valve'in a different position.

The embodiment of the invention chosen for the purpose of illustration comprises a closed handle indicated generally by A and provided at one end with asocket or sleeve connection Bto be secured in any suitable manner to a part of a pneumatic tool such as the cylinder X of a riveting hammer, and

provided at. its other end with a hand grip portion. C. Intermediate the parts or ends B and C is an open space to accommodate the fingers'of the operator. Through the lower portion of the hammer extends a mo-' tive fluid passage or conduit 3 which terminates in the live air chamber 4 of the socket end B of the handle. Conduit 3 is inter-- sected by a bore -5 extending through the grip portion G. Inserted in bore 5 with a press fit is a bushing 6 having its lower end inwardly bevelled to form a seat 7 for a throttle valve 8 of the poppet type which is normally maintained in contact withseat 7 by coiledfspring 9 surrounding a projection 8 on the head of the valve and interposed between the latter and a plug 10 closing the lower end of bore 5. Bushing 6 in- Other objects will be ap'-.

(in its dotted line tersects conduit 3at an angle so that the valve 8 is arranged-to stop the supplyo'f motive fluid when against its seat .7, a port '6 being provided in theibushing beyond fluid to live air'chamber' 4. when the valve the valve seat to permit theflow of motive 8 is open. If desired an inner bushing 11 within bushing 6 may be provided for the stem of valve 8.

The means for' moving valve" 8 from its seat comprise a plunger 12 fittingv the upper end of bushing 6 and extending therebeyond, a leve'r'13 having: a'shoulder 13?. adjacent its pivot end engaging plunger 12and an ex tension 13 remote from thepivot end and disposedv substantially at a right angle to the longitudinal axis of the lever, and a trigger lever 14'pivoted at 14 and having a cam extension 14 for cooperation. with extension '13 of lever 13 and a trigger end 14 extending into the'open space between parts B and C of the handle. The parts are so arranged that'the cooperating levers 13and 14 are always in engagement with the annular surface of the pivot end of lever 14 serving as a stop for 'the end of extension 13 of lever 13 thereby to maintain, plunger 12 in place and the coacting parts 12, 13'and 14 ready for instant movement. extension 14 of trigger lever 14 is so dis-' The cam posed as to .pe'rmit'a limited free movement of the latter wlthout actuating the lever 13,

the extent of this movement being indicated by the full line and dotted line positions of lever 14 in Fig. 1. This. limited free movement of lever 14 enables the operator 'to' grasp the grip portion C of the handle be-' hind trigger 14 when the latter is in the full line position ofFig. 1 so that the tool can be easily carried without danger of its being accidentally operated, and it also provides room for two or more fingers of the operator to bepassed over the trigger 14*" I position) preparatory to operating the tool."

From the above it will be apparent that the mounting of the throttle valve mecha nism in the gripportion of a "handle of this type, rather than in the socket portion as heretofore makes a lighter and-more compact handle, that the continuous engagement of the intermediate lever withthe valve plunger on the one hand and with the trigger lever on the'other not only retains the former in place but avoids lost motion in the r v v 1,16,99?

valve operating mechanism when the valve is to be operated and permits accurate control of the motive fluid supply, and that the arrangement for limited free movement of the trigger lever attained withoutsacriiice of the advantages just enumerated permits the tool to be easily carried without danger of accidental operation and also provides clearance for the operators lingers over the trigger when the tool is to be used.

I claim as my invention X l. The combination with a fluid pressure tool of manual controlling and supporting means therefor comprising a handle device Lil secured at one end to the tool and having a grip portion at the other end, a motive 'fluid connection through said device to the means therefor comprising a handle device secured at one end to thetool and having a grip portion at the other end,a motive fluid connection through said device to the tool, throttle valve mechanism in the grip portion of said "device for controlling the motive fluid supply, a trigger lever. extending into the space between the ends of said device and movable toward said grip portion, and means for operating said throttle valveon movement of said lever, said means being arrangedto permitlimited tree movement of said lever to provide clearance under thesame for the operators fingers when the tool is to be carried and for his fingers over the lever when the tool is to be operated.

3.;The combination with a fluid pressure tool of manual controlling and supporting means therefor comprising a handle device secured at one end to the tool andhaving a grip portion at the other end, a motive fluid connection through said device to the tool, said grip portion having a bore intersecting said connection, a throttle valve mounted in said bore, a lever disposed in said grip portion for actuating said throttle valve, and a lift trigger lever extending into the space between the ends of said device arranged to actuate said throttle control lever. I

4a. The combination with a fluid pressure toolot manual controlling and supporting means therefor comprisn a handle device b secured at one, end to the tool and hav ng a grip portion at the other end, a motive fluid connection through said device to the tool, said grip portion having a bore intersecting said connection, a throttle valve mounted in, said bore, a lever disposed in said grip portion for actuating said throttle valve, and a lift trigger lever extending. into the space betweenthe ends of said device for actuation by-the operator and having a cam secured at one end to the tool and having a grip portion at the other. end, a motive fluid connection'through said device to the. tool, said grip portion having a bore inter-- seating said connection, a throttle valve mounted in said bore, a lever disposed in said grip portion for actuating said throttle valve, and a lift trigger lever extendingintothe space between the ends of said device for actuation by the operator and having a cam projection to engage and actuate said throttle lever, the pivot end of said trigger lever serving as a stop for said throttle lever when the former is in inoperative position, said cam projection'be'ing so disposed onsaid trigger lever as to permit lnnitedmovement of the latter relative to the throttle lever without actuating the same.

6. In a handle for fluid pressure tools a motive fluid conduit therein, a throttle valve in the ri. ortion of said handle for con-1 trolling said conduit, coacting levers for actuating said valve, means maintaining said levers continuously in engagement with each other, one of said levers being arranged for manual operation, said last named lever being arranged for limited movement without actuating said other lever. v

7. A handle'arranged to be secured to a fluid pressure tool having a motive fluid conduit therein and a bore in the grip portion of said handle intersecting said conduit, a bushing in said bore, a poppet valve cooperating withsaid bushing and controlling the motive fluid supply,a plug sealing one end of said bore, a spring interposed between said plug and said valve normally to maintain the valve in closedposition, a plunger in the oppositeend of said bushing, a lever dis posed within said grip portion and having a shoulder adjacent its pivot end engaging said plunger and an extension remote. from said pivot end. and at an angle to the longitudinal axis thereof, and a trigger lever arranged for manual operation and having a cam portion for engagement with said extension of said first named lever.

8. A closed throttle handle for a fluid pressure tool having a motive fluid conduit therein and a bore in the grip portion of said handle intersecting said conduit, abushing in said bore, a poppet valve reciprocable in said bushing and controllng the motive fluid. supply, a plug sealing one end of said bore,

a spring interposed between said plug and said valve normally to maintain the valve in a closed position, a plunger in the opposite end of said bushing, a lever disposed within thereof, a trigger lever extending within the central opening of the handle and having a cam portion for engagement with said extension of said first named lever, said cam portion being'so disposed as to permit limited free movement of said trigger lever, the pivotend of said trigger lever forming a stop for said extension whereby said first named lever operates to retain said plunger in place; 7

Signed by me at Detroit, Michigan, U. S. A., this 16th day of April, 1925.

EDWARD W. STEVENS. 

